Our earlier U.S. Pat. No. 7,137,982, the contents of which are herein incorporated by reference, describes an electrosurgical instrument for spinal procedures comprising a generally scoop-shaped cup whose periphery is electrically active and is capable of applying RF electrosurgical currents to spinal tissue. The active electrode may comprise an exposed bare wire at the leading edge of the cup. A conduit in a handle section can convey suction to the cup. A tissue clearing member is pivotably mounted on or inside the cup and can be manipulated via a lever on the handle to help dislodge tissue. The tissue clearing member may be a radially-extending vane for rotation in the plane of the cup edge. The tissue clearing member may also be made electrically active thus selectively providing unipolar or bipolar operation. The surgeon can exercise control of tissue vaporization as the focused energy emitted from the scoop-shaped electrode is rapidly and locally absorbed and liquefies the cells.
While the patented device is suitable for many spinal procedures, there is a need in the art for an instrument that can electrosurgically remove tissue, and specifically disc nucleus pulposus, via a cannula for minimally invasive surgical (MIS) procedures.